Material handling system



R. E. CALLER MATERIAL 'HANDLING SYSTEM Nov. 13, 1934.

Filed July 15, 1931 2 Sheets-Sheet l INVENTO]? AYMONDZ CHLLEE ATTORNEY NOV. 13, 1934. I REE, CALLER v 1,980,782

MATERIAL HANDLING SYSTEM Filed July 15. 1931 2 Sheets-Sheet 2 J??? 10. BAYM zmf $31 252 ATZ OJPNEY Patented Nov. 13, 1934 UNETED STATES PATENT oFFics MATERIAL HANDLING SYSTEM Raymond E. Caller, Scarsdale, N. Y.

Application July 15, 1931, Serial No. 550,972

8 Claims.

This invention relates to improvements in dusthandling systems actuated by combined pneumatic and mechanical means and designated as self-clearing main systems. I'hey are used for collecting miscellaneous materials, including dust and the larger and heavier constituents of waste.

In the term dust is included the smaller and lighter materials that ordinarily are held in suspension in a body of air flowing through a duct.

Examples of waste are, in the woodworking industry, bark, hogged chips, sawdust, shavings, splinters, chunks and blocks, by-products of cutting and sawing machines. As a further example, in the shoe manufacturing industry, such waste is made up or leather shavings and clippings.

My present improvement is adapted to be incorporated in a dust handling system of the kind described and claimed in Patent No. 1,610,358, issued to me December 14, 1926, which discloses a principal trunk line or pipe, called the main, a plurality of smaller branch receiving pipes or ducts connecting the main to the machines being servedthe combined cross sectional area of the branch ducts being less than the cross sectional area of the maina fan for exhausting air from the main, and a drag conveyor running lengthwise within the main.

The exhaust fan, driven by an electric motor, produces in the branch ducts sufficient air velocity to carry the miscellaneous material into the main, but produces in the main itself insumcient velocity to move the heavier constituents of the material through the main. The dust goes into the fan and is discharged through a cyclone dust collector while the heavier constituents-of the miscellaneous material drop to the bottom of the main and the drag conveyor moves them along the main until a delivery-opening is reached where the heavy material falls into an air-trapped boot in known manner. Sometimes the delivery opening is omitted. In that case the heavier constituents are pushed by the conveyor along the main into the fan, and are driven thence through the cyclone to discharge with the dust.

In the structure of the above mentioned patent the main was in the form of a long straight tube or conduit. charge outlet for heavier material were located at an end of the conduit. The main clearing conveyor was an endless chain presenting a lower working run and an upper idle return run, both being concealed within the main and carrying suitably spaced drags or flights.

The patented system was quite satisfactory in practical operation, requiring only a relatively Both the exhaust fan and the dissmall amount of power to operate it, and its maintenance cost was slight in comparisonwith that of the all-air systems theretofore used. My present inventionemploys the same primary elements as the system of the patent, namely, a main, an exhaust fan and a conveyor arranged for impelling heavymaterial along the bottom of the main. It diiiers, however, in certain important features of structure and mode of .operation, and has as its object to improve the earlier system in the following respects: Greater adaptability to suit changed plant conditions, such as rearrangement of the machines to be served, simpler and cheaper construction, compactness, less power required for handling a given amount of material per unit of time and improved operating efliciency of the mechanical conveyor within the main.

These objects are attained by arranging the main to present an endless duct, preferably in, the form of a loop or closed circuit, instead of the straight line duct heretofore used. The fan or other exhauster can be applied at any con- Venient place throughout the length of such an endless duct instead of necessarily being applied at or near its end as was the case when a straight main was used. This endless or so-called continuous circuit main admits of increasing or decreasing the number of machines served by any stated section or zone of its length, and such increase or decrease may be of any desired amount within the capacity for which the installation is initially designed. Moreover, the original number of machines can be regrouped at will along the main without risk of overloading any part of the system. Such regrouping does not require the main to be rebuilt or altered in respect to its cross sectional dimensions, nor does it entail any change in the general plan or' routing of the main. Thus, the adaptability or flexibility of the main to suit arbitrarily altered conditions of operation has been-greatly improved.

With a main of the endless type herein described the conveyor' need have but one working run and no idle or return run. Consequently all of the conveyor mechanism is usefully employed instead of only half of it, as heretofore. A very large factory area of any form can be served by one chain drive mechanism andonechain take-up. Hence the construction of the conveyor for complex installations is simplified and cheapened. Ordinarily only one fan is needed to serve the entire loop. It does the work of three or four straight .mains; hence compactness is attained. The conveyor flights, bef 110 ing always close to the bottom, offer minimum obstruction to air flow along the main. Undesirable baflling effects and consequent waste of power caused by the resistance to air flow, formerly produced by an upper run of idle return flights is avoided. The entire movement of the chain is in a substantially horizontal plane, as distinguished from the upper and lower conveyor runs heretofore employed. Therefore, the chain and its flights can be made town in any desired circuitous path, including right and left turns, U-turns, angle turns and, if desired, ogee curves. By reason of the fact that an endless circuit main can easily be installed to run inany horizontal direction and in any plan or pattern desired, the main can be positioned so as to pass quite close to the machines being served. Obviously, close proximity of the main to the machines reduces the amount of work required to be done by the exhaust fan in lifting the miscellaneous materials from the machines into the main. A long circuitous -main of the endless type herein described can have uniform cross sectional shape and area throughout its length, rendering unnecessary the use of reducing or tapered sections and enabling the main to be built at less cost.

With the foregoing and certain other objects in view which will appear later in the specification, my invention comprises the devices described and claimed and. the equivalents thereof. For purposes of description a mechanical chain drive is here shown as a preferred means for driving the heavier constituents along the main, but any other type of material impelling device may be used if desired without departing from my invention as set forth in certain of the appended claims. As an example of such alternative type of conveying means, individual jets mechanism.

of steam or air under pressure, or a reciprocating scraping conveyor may be used actuated either continuou'sly'or intermittently. v

In thedrawings Fig. 1 is a top plan View of a typical system wherein the circuit main is arranged in rectangular form.

is a top plan view illustrating a modifled arrangement that is typical of the various shapes that can be assumed by the main to suit variously distributed machines to be served.

Fig. 3 is a still further modified form.

Fig. 4 is an end elevation of an installation similar to that shown in Fig. 1, as seen from one end.

Fig. 5 is an enlarged plan View of the drive Fig. 6 a side view of the conveyor drive mechanism.

Fig. 7 is a plan view of the take-up corner of the main with itsfltop cover broken away.

Fig. 8 is a sectional view of a preferred form of main.

Fig. 9 is anenlarged side view, partly broken away, showing the drag chain illustrated in Fig.

. 8", with the brackets and flights attached thereto.

mechanisms at all of the corners and angles are of like construction, but the driving mechanism for each kind is different.

The corner C at which the main conveyor drive is applied is provided with a vertical shaft 1 running in upper and lower bearings 2, 3, the shaft extending at each end beyond the bearings. At the lower end of the shaft is a sprocket 4 with which the chain 5 meshes.

The chain travels throughout its circuit at a considerable height above the flights 6 and above the layer of blocks, chips and miscellaneous materials in order to prevent them from becoming wedged in the links Where they mesh with the corner sprockets. Any suitable drive may be applied to the upper end of the shaft 1 to rotate it at slow speed,.producing a preferable chain speed of about thirty feet per minute. The drive as illustrated comprises the sprocket '7 driven by a chain 8 from another sprocket 9 which is mounted on a vertical shaft 10. Thelower end of shaft 10 carries a bevel gear 11 which is driven by a bevel pinion 12 mounted on a horizontal shaft 13 carrying a pulley 14' driven from any suitable source ofpower.

With the exception of the corner D at which the conveyor take-up is located, and the corner C at which the power drive for the conveyor is placed, all of the corners of the main are equipped as above described with vertical shafts mounted in suitable bearings, each shaft carrying a sprocket, but these shafts are driven by the drag chain 5.

At corner Don the slack side of the chain, is a shaft 15 carrying a sprocket 16 which is mounted in suitable bearings slidable upon a tightener frame 17 of known construction.

It is apparent from inspection of Fig. 8 that the flights should follow quite closely the center. line of the bottom of the main A, B, and when the tightener is adjusted to take up slack in the chain the location of the tightener sprocket 16 is changed as indicated by dotted lines in Fig. 7, and the direction of the flights leaving the sprocket becomes off-center with respect to the adjacent straight run. To keep the chain on the desired center line a vertical shaft 18 is mounted in suitable bearings within the main and carries a sprocket 19 at its lower end, the sprocket being positioned so that the chain leaving it must travel the center line'of the main. The conveyor within the clearing circuit main may be operated either intermittently or continuously according to the volume of heavy materials accumulating in the bottom of the main.

By making the main in the form of an endless machines are connected to the main at some point near the exhauster, their ducts may let such an over-supply of air into the main at that point that the more remote machines on the same main will be handicapped for lack of suction. But no such handicap can exist in an end- 1 less loop main, such as herein described, for the remote machines get adequate suction from around the loop in the other direction to pull the miscellaneous materials from these machine into the main.

Obviously, therefore, it is impossible for any condition of normal operation of the system to arise where the looped main can fail to clear all of the branch ducts provided the exhauster is of proper capacity to pull the peak load.

The main exhaust fan 20 is of suflicient capacity to handle whatever peak loads of material may be fed to it from the circuit-clearing main A, B, but if the loads in the branch ducts 21 should require greater suction capacity than the main exhaust fan 20 is capable of handling, then one or more auxiliary fans 22, attached at convenient points along the main A, B, may be put into action to produce added suction and velocity in the branch ducts 21.

An advantage of such an auxiliary fan is that it is permissible to employ a smaller main than would be required if only one principal exhaust fan were used.

One or more auxiliary fans 22 may be provided, each having its intake opening connected to the trunk by a pipe 23, its discharge opening being connected to a cyclone dust separator 24 that in turn is connected to the trunk A, B. The auxiliary fans 22 are connected to the upper part of the main where only dust and lighter materials are traveling. The light material is removed from the main by the fan 22 and is returned to it at a more advanced point, the air i in which the dust was suspended being discharged to the atmosphere.

The heavy material carried along the bottom of the main by the conveyor is discharged through an outlet at any desired point in the system, as

I for example, at an air-trapped discharge opening 25 into a boot 26 in main B, indicated by the dotted rectangle in Fig. 1. If desired a plurality of such discharge outlets may be located at different points in the circuit. Fig. 10 shows Iin side elevation boot 26 communicating with opening 25 in the bottom of main B and arranged to discharge by gravity into a bin or receptacle 27 shown in solid lines. Bin 2'7 is closed to trap out the outside air which would otherwise be T drawn into the main B. Various other known air-trapping devices may be employed for this purpose. For example, discharge may be effected through an exhaust fan into a conventional separator (not shown). In this device the fan 1 serves to prevent the ingress of air to the main B.

The air current carrying the lighter particles and dust may travel in either direction toward the main exhaust fan or to any auxiliary exhaust fan or fans. In systems of unusual length an auxiliary fan may be employed as a booster, drawing air from the main and returning it to the main farther along at increased velocity.

In Fig. 3 I have shown diagrammatically an endless main with an endless conveyor therein,

j similar to Fig. 1, but having a centrally disposed double sized trunk A, served by two runs 560, 5b, of the conveyor, passing in opposite directions, as indicated by the arrows. The flights of these two runs merely pass each other, and the material being moved by them can be delivered through any suitable outlet, as the opening 25 described above. If desired an exhauster 2011 can be applied to the central or inwardly projecting trunk member.

An endless main arranged in loop form in the manner above shown and described has advantages where an old dust-collecting system is to be remodeled. Assume a plant which was originally equipped with a number of straight .tubular mains such as are shown in my previous patent, or even with tubular mains operating according to the old so-called all-air system. Each main necessarily had its own exhauster located at its material discharge terminus.

-When the straight mains are removed and a circuitous endless duct, made according to my present invention, is installed in their stead, it is not necessary to incur the expense of removing the original exhausters, nor even to change their location, because the endless circuitous main can be run into the neighborhood of the existing exhausters so they can be readily connected to it. Thus each main exhauster of the old system becomes operative as an exhauster unit of the new endless loop system.

If the normal working load on the main is not great enough to require all of the old exhausters to be operated at full capacity, one or more of them can be left idle, the load being carried by the remaining exhauster.

If the aggregate of waste material is to be delivered at a certain location, say, at a place in the plant nearest the boiler room, the discharge pipe of the system can be attached to whichever exhauster is nearest the boiler room.

If sometime it becomes desirable to discharge the material in another direction, due to rearrangement of the plant, then it is only necessary to use one of the other exhausters for the discharge element of the system. The continuous working run of the conveyor will deliver equally well into any selected outlet from the main.

It is thus seen that any amount of suction can be maintained at any point in the loop main and that material can be discharged at any place along its length, thereby imparting to the system the utmost of adaptability and flexibility of operation to suit present or future requirements of the plant in the handling of waste material.

In the appended claims, I have pointed out the essential elements of my invention, it being understood, however, that the claims are not intended to be limited to the form of the parts illustrated and described further than a limitation to the described form is necessary to distinguish them from the prior art.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a dust collecting system a self clearing main comprising a tubular duct forming a loop, branch supply pipes communicating therewith, air exhaust means communiting with said duct, an outlet in said duct positioned to discharge material from the loop, and a material conveyor operative within said duct.

2. In a dust collecting system a self clearing main having branch supply pipes and a discharge outlet for heavier materials, said main comprising a duct forming an endless loop, in combination, air exhaust means in communication with said duct, and a material conveyor having flights constrained to travel throughout the length of said loop along its bottom in a continuous material engaging circuit past said discharge outlet.

3. In a dust handling system for conveying material heavier than air and lighter particles thereof, which includes a main trunk line presenting an endless substantially horizontal loop having a discharge outlet and a plurality of smaller branch ducts connected thereto, means adapted to withdraw air from said trunk line at sufiicient rate to produce in said ducts velocity to move said heavier materials through said branch ducts only, and a mechanical conveyor extending throughout 4. A dust handling system for conveying miscellaneous materials composed of heavier and lighter particles which includes a main trunk which forms an endless tubular loop composed of angle portions and straight portions joined, means for discharging material from said circuit trunk, branch ducts for delivering material into said trunk, means for creating air flow through said branch ducts sufiicient to convey the material therethrough and deposit it in the main trunk and a material conveyor operative throughout said endless tubular loop, said conveyor including a take-up device and means for constraining the conveyor to travel in a central path along said trunk.

5. A self clearing main having branch pipes and an air-trapped material discharge outlet, said main comprising an endless duct disposed substantially horizontally in loop form, an exhauster in communication with said duct adapted to maintain a partial vacuum therein,'and a material conveyor comprising a chain carrying flights within said duct mounted below the chain so as to travel in a continuous working circuit throughout the duct and in proximity to said outlet.

6. A dust handling system for conveying miscellaneous materials, having in combination a main forming a closed loop, receiving ducts communicating therewith, a conveyor in said main consisting of a single endless working run operative throughout said duct, conveyor actuating means, and means maintaining suction in said duct.

7. In a dust handling system, in combination, an endless tubular main having supply ducts connected therewith, a conveyor therein consisting of asingle endless Working run operative throughout said tubular main, said conveyor comprising flights and a chain spaced above said flights, and guiding pulleys, take-up sheaves and driving means operatively associated with said chain.

8. A continuous circuit'main presenting an end-' less tubular duct in the form of a loop, an exhaust fan connected to said duct, an endless conveyor extending through the length of said duct to provide a singlecontinuousworking or material handling run, driving mechanism for actuating the conveyor, conveyor pulleys Within the duct, a take-up device for the conveyor with.- in'the duct, and a guide sprocket associated with the take-up and adapted to constrain the conveyor to follow the center line of the duct.

RAYMOND E. CALLER. 

